What is the meaning of Spinel?

Any of several hard minerals of cubic symmetry that are mixed oxides of magnesium and aluminium and are used as gemstones of various colours.

Any crystalline material, not necessarily an oxide, that possesses the same crystal structure as this mineral.

(Can we verify this sense?) Bleached yarn in making the linen tape called inkle; unwrought inkle.

Source: wiktionary.org

See also